Genetic Causes of Primary Amenorrhea Using Chromosomal Analysis and PCR for SRY Gene

Abstract

Background Primary amenorrhea (PA) is defined as menstruation by age 14 without secondary sexual characteristics or by age 16, regardless of normal development. Although several etiologic factors were incriminated, chromosomal aberrations occur in 14-60% of cases. This study aimed to evaluate the chromosomal abnormalities in patients with primary amenorrhea referred to Elite Genetics Center, Khartoum-Sudan, for genetic analysis. Methods Between 2017 and 2023, 248 patients with PA were investigated. Clinical data, hormonal profiles, and sonographic findings were recorded. Karyotyping was done as an initial test, and PCR analysis for the SRY gene was used as a complementary test for patients with normal karyotypes. The clinical diagnosis was based on the history, clinical presentation, hormonal investigation, sonographic findings, and cytogenetic and molecular results. Results The results showed that 68 (27.4%) had female karyotypes (46,XX), and only 36 (14.5%) showed male karyotypes. Numerical chromosomal abnormalities were seen in 97 (39.1%) cases, whereas structural changes were seen in 14 (5.6%). Turner syndrome was present in 137 (55.2%), Trisomy X chromosome (47, XXX) was in 3 (1.2%) cases, and sex reversal (46, XY) was in 7 (2.8%) cases. Clinical diagnosis of XY DSD was in 21 (8.5%), Complete Androgen Insensitivity Syndrome in 8 (3.2%), Sawyer’s syndrome in 7 (2.8%), Ovotesticular DSD in 4 (1.6%), Mayer-Rokitansky-Küster-Hauser syndrome in 5 (2%), and Triple X in 3 (1.2%) cases. Conclusion The results showed the need for cytogenetic analysis as an integral part of the PA diagnostic protocol. Complementary PCR for the SRY gene is essential in differentiating XY DSD cases.